The cerebral hemispheres of the human brain appear to be specialized to handle information in different ways--the left operates predominantly in a verbal-analytic mode, the right in a spatial-synthetic mode. EEGS from the hemispheres are different when Ss engage in tasks involving the two cognitive modes. Previous investigations on this grant showed the EEG asymmetriis are trivial because they are systematically related to overt performance in reaction time and complex visuomotor coordination tasks. The goals of the proposed research are to further explore EEG asymmetry and performance relationships and examin asymetry during periods of long task engagement during automizaton of complex performance. Factor analysis of evoked potentials will be used to study interactions of cognitive tasks and motor set on performance. Complementary hemispheric specilization will also be studied in terms of its maturation, its role in deveopmental dyslexa, and sex differences.